Electrical signals often contain undesired signal portions (e.g. due to nonlinearity or mismatch) or deviations of signal portions from desired properties (e.g. amplitude or power) caused by the signal processing and/or varying environmental conditions. For example, an uplink cellular transmission may be confronted with signals having strong amplitude modulation and different modulation schemes, showing a variety of different crest factors and also different spectral contents. For example, the signals may range from very narrowband signals like LTE (Long Term Evolution) with single resource block occupation to LTE 20 with full allocation. It is desired to provide signals with properties as close as possible to desired signal properties.